Electric furnace.



J. B. TRILLON.

ELECTRIC FURNACE.

APPLICATION FIL D JULY 6. 1907.

932,885. Patented Aug. 31, 1909.

2 SHEETS-SHEET 1.

J. B. TRILLON.

ELECTRIC FURNACE.

APPLICATION FILED .TULYB, 1907.

932,835, Patented Aug. 31, 1909.

2 SHEETS-SHEET 2.

w i y uilui i i T i i {p L 7X T 'J U WIN/[55% of voltage in the line.

JEAN BAPTISTE TRIIlLON, OF ST. J'EOIRE, FRANC TROGHIMIQUE DU GIFFRE E, ASSIGNOR T0 HIMSELF AND OF ST. J'EOIRE, FRANCE.

LA SOCIEE'IE ELEG ELECTRIC FURNACE.

Specification of Letters Patent. Application filed July 6, 1907.

Serial No; 382,534.

To all whom it may concern:

Beit known that I, JEAN BAr'rIsTE TRIL- LON, a citizen of the Republic of France, and resident of St. J eoire, France, have invented new and useful Improvements in Electric Furnaces, which improvementsare fully set forth in the following specification.

The electric arc furnaces which have received practical applications almost come under two categories: 1. Those with a single are or several arcs working in parallel betweentwo electrodes or two batteries of electrodes of opposite polarities; or between one or more electrodes forming one of the poles, and the sole of the furnace or the substances to be treated forming the other pole. 2. Those with two arcs in series formed for example between the conducting bath and two carbon electrodes -of opposite polarity and adjustable separately.

In the first case the intensity of the current and the voltage at the terminals are easy to regulate, but this pressure cannot hardly in practice exceed or 70 volts, so that it is necessary rent intensities which are frequently considerable, which cause serious losses or fall In the second case, these losses are avoided for the greater part by the employment of a double voltage or tension, but great difficulties arise in main taining the two arcs absolutely at the same regimen, and in preventing their interruption any variation in one of them reacting upon the other, and the interruption of one causing the extinction of the other. This is equally true when in place of arcs only the materials to be treated are to be rendered incandescent by the passage of the current.

The present invention has for its object a form of electric furnace termed a three-' wire electric furnace possible to diminish the losses in the line by the employment of two ormore arcs or hearths in'series on the one hand, while ontheother hand providing for an independent existence and regulation of each are or hearth. This arrangement consists broadly in employing electrodes of opposite polarity for the normal supply and the return of thecurrent, but with this peculiarity that the sole of the furnace or the conducting bath forming part of the circuit is connected electrically to an appropriately selected oint of the generating circuit, by means 0 a conductor to have recourse to ourby means of which it is which is not normally to reconduct the dif- Patented Aug. 31, 1909.

ferential current to the generators in case I the intensity of the arcs or hearths 1s unequal,

or the total current in case one of the arcs is interrupted.

, My invention is illustrated in the accompanying drawings, in which similar reference letters denote corresponding parts and in which Figures 1 and 2 show the diagrammatic views of an electric furnace fed, re spectively, by a continuous and alternating current.

In this drawing A represents in section the furnace chamber formed in the ordinary manner of refractory materials, and provided if desired with a tapping hole. B is one of the movable electrodes operated mechanically or by hand in such a manner as to regulate the intensity of the corresponding are by varying the distance between the extremity of the electrode and the sole of the furnace C or the conducting bath D. E is a second electrode arranged like the firstand adapted to be displaced independently. The drawing also shows that the current, which in this example is producedby two dynamos arranged in series,'enters at one of the electrodes, passes through the bath or the sole of the furnace and returns to the generator group L, M through the second movable electrode. Nevertheless, in case one of the arcs should be reduced or extinguished, the current is able to return either wholly or in part I by the third conductor 0, connecting the sole of the furnace to a pointon the generating circuit located between the two dynamos. This sole may be composed of a metal plate or frame to.which the conductors are fixed; it is covered with a refractory material which is a good conductor of electricity and a bad conductor of heat, such as an agglomerate of retort carbon or graphite In cases in which the contact of the graphite with the metal or other product forming the bath at the bottom of the furnace presents difliculties, another form of contact may be adopted.

It should be understood that according to requirements the furnace may or may not be provided with an arch or cover with aper-. tures for the passage of the electrodes; that the electrodes may be vertical or more or less inclined; that the furnace chamber may or may not be divided by an insulating and refractory partition F, forming a bridge above by adjusting the G, H, in such manner described above enables all operawithout passing through the liquid. bath.

" dotted lines;

those described in the first instance when constructions heretofore employed:

thebath and preventing the passing from one electrode to the other through the charge to be melted or reduced, diminution of the cost of installing the line i as only one return conductor is employed i for two arcs instead of two. (1)) diminu tion of the line losses due to resistance, as a 1 double voltage is employed, and normally i only two conductors are traversed by the current.

2. Relatively to These various detailmodifications do not in any way affect the principle of the invention, which consists broadly in the application to electric furnaces of the method of connection termed the three-wire arrangement.

The operation of the furnace is regulated two electrodes in accordseries: (d) great the indications of the ammeters avoidance of racing of the generators ue to a manner that the two coninterruption of the current, if care be had ductors I and J are traversed by equal curto couple the said generators mechanically rents as far as possible. A voltmeter K inor to control them by one and the same dicating the total voltage at the terminals of replacing wornmotor. (6) possibility may be connected between these two conout electrodes in succession without interductors.

rupting the operation of the furnace. (f) In Fig.2 the electric furnace is shown'as being fed by an alternating current. Here L denotes the inductor developed by an alternator which for simplicitys sakeis shown as having two poles N and S, but which of: course may have any number of poles. The inductor consists of two coils, one 0 marked by full lines, and the other P marked by The coils end, respectively, at Q, R and- T U. In accordance with the law governing the alternating currents the ter minals in question will, at a certain moment, become instantaneously of a positive or neg-- ative polarity. If the terminal'Q, of the coil 0 is electrically connected with the electrode B of the furnace and the other terminal T of the coil P to the electrode E, and if the terminals R and U are both at the point of X electrically connected with the sole of the furnace the same effects will be obtained as furnaces with two arcs in stability in operation; ance with intensity of each are or hearth and if necessary of causing the whole or a portion 0 current to pass electrodes and the mass turn taking third wire, eitherfor the purpose of heating the bath to a greater extent at a given point, or of producing a more efficient distribution of the heat in the mass in fusion if it is deep.

I claim- An electric furnace comprising at least two independently adjustable electrodes of opposite polarity, and in which the sole and conducting bath form a part of the generating circuit and at-;least two hearths are formed, and a third conductor between ,sai sole and a selectedpoint of the generating circuit to allow of the return of the electric \current wholly or partly through said third conductor. p

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

JEAN BAPTISTE TRILLON. .Witnesses:

Y L. H. Munnin, D. YU LIN.

continuous current is used.

An electric furnace constructed in the tions of which are or resistance furnaces are capable to be efiected, and presents the following advantages as compared with the finally the possibility of varying at will the place through the sole and the.

currentfrom 1. Relatively to furnaces with one are or several arcs in parallel: (a) Considerable fthe 

